The use of bone marrow transplantation (BMT) for treatment of pediatric malignancies has increased exponentially over the past decade. Currently, more than 2,000 BMTs are performed annually in the U.S. on children and adolescents and continued increase in rates of BMT are expected. BMT is an intensive, physically demanding treatment regimen, which represents a very significant stressor for patients and families. Despite numerous clinical reports of maladaptive psychosocial responses to BMT, empirical data available regarding specific behavioral and psychosomatic outcomes of BMT in pediatric populations is lacking. Obtaining this empiric data is essential for the development of preventive interventions and effective programs of psychosocial support for BMT. patients. The primary goal is to identify the behavioral, affective and somatic sequelae of pediatric BMT during the acute phase of determinants of patient response to BMT will be analyzed in the context of a risk- resiliency model, to identify protective factors that promote healthier psychosocial outcomes. Data from this study will advance clinical practice promote our understanding of childhood resiliency. This will be accomplished using the prospective, longitudinal design, with assessments that begin pre-transplant, and continue for 3 years post-transplant. Data obtained pre-transplant includes baseline measures for longitudinal comparison, as well as psychologic predictor variables. Potential protective factors to be studied include: a) child disposition (locus of control, coping style, cognitive style); b) family environment (cohesion, conflict, expressiveness, and the coping behavior of the resident parent); and c) external social support resources. The major focus of data collection will occur during the acute phase of BMT hospitalization through the transition period of the first 6 months post-transplant. Repeated measures data regarding the patients' somatic, behavioral and affective responses during this period will be utilized both as an outcome of primary clinical interest and as a predictor of later outcome. Long-term outcome will be assessed with comprehensive measures of patient social competence, behavioral adjustment, and emotional wellbeing, as well as psychoeducational function. The proposed studies will advance clinical care through identification of a) specific clinical problems and the factors associated with their occurrence, and b) specific high risk subgroups for whom interventions should be targeted. It will advance theoretical understanding of child coping processes and protective mechanisms which promote resilience against significant childhood stressors.